MSP430G2X21 Datasheet, PDF (31/61 Pages) Texas Instruments – MIXED SIGNAL MICROCONTROLLER

MSP430G2x21, MSP430G2x31
MIXED SIGNAL MICROCONTROLLER
SLAS694B -- FEBRUARY 2010 -- REVISED MAY 2010
electrical characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (continued)
10-bit ADC, external reference -- MSP430G2x31 only
VEREF₊
PARAMETER
Positive external reference input
voltage range (see Note 2)
TEST CONDITIONS
V_CC
VEREF₊ > VEREF_--
SREF1 = 1, SREF0 = 0
VEREF_-- ≤ VEREF₊ ≤ V_CC -- 0.15V
SREF1 = 1, SREF0 = 1 (see Note 3)
MIN TYP MAX UNIT
1.4
V_CC V
1.4
3.0 V
VEREF_--
Negative external reference input
voltage range (see Note 4)
VEREF₊ > VEREF_--
0
1.2 V
∆VEREF
I_VEREF+
Differential external reference input
voltage range
∆VEREF = VEREF₊ -- VEREF_--
VEREF₊ > VEREF_-- (see Note 5)
0V ≤ VEREF₊ ≤ V_CC,
SREF1 = 1, SREF0 = 0
3V
Static input current into VEREF₊
0V ≤VEREF₊ ≤ V_CC -- 0.15V ≤ 3V
SREF1 = 1, SREF0 = 1 (see Note 3)
3V
1.4
V_CC V
±1
µA
0
µA
I_VEREF--
Static input current into VEREF_--
0V ≤ VEREF_-- ≤ V_CC
3V
±1
µA
NOTES: 1. The external reference is used during conversion to charge and discharge the capacitance array. The input capacitance, C_I, is also
the dynamic load for an external reference during conversion. The dynamic impedance of the reference supply should follow the
recommendations on analog-source impedance to allow the charge to settle for 10-bit accuracy.
2. The accuracy limits the minimum positive external reference voltage. Lower reference voltage levels may be applied with reduced
accuracy requirements.
3. Under this condition the external reference is internally buffered. The reference buffer is active and requires the reference buffer
supply current I_REFB. The current consumption can be limited to the sample and conversion period with REBURST = 1.
4. The accuracy limits the maximum negative external reference voltage. Higher reference voltage levels may be applied with reduced
accuracy requirements.
5. The accuracy limits the minimum external differential reference voltage. Lower differential reference voltage levels may be applied
with reduced accuracy requirements.
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